Elevator safety device



2 'SheetsSheet 1.

(No Model.)

C. R. PRATT.

ELEVATOR SAFETY DEVICE. No. 580,894. Patente dApr. 20, 1897.

. 9 'av Wilnesses= Inventor, I harlas Pra kt,

W 1 b 2% I m j v Al arr 1i Patented Apr. 20, 1897.

2 t e e h S m. e e h s 2 E m d 0 M 0 w Witnesses (5M I Charles l -lPratt- UNITED STATES PATENT OFFICE.

CHARLES R. PRATT, OF MONTOLAIR, NEW JERSEY, ASSIGNOR TO THE 'SPRAGUE ELECTRIC ELEVATOR YORK.

COMPANY, OF NEIV YORK, NEIV ELEVATOR SAFETY DEVICE.

SPECIFICATION forming part of Letters Patent No. 580,894, dated April 20, 1897.

I Application filed December 17, 1896. Serial No. 615,989. (No model.)

' of two safety-catches operated by a spring,

which is released by the. governor, in combination with other elements, as hereinafter claimed.

Referring to the accompanying two sheets of drawings, which form a part of this specification, Figure l is a side view, partly in elevation, showing the safety device attached to the bottom of the car and engaging the car-' guides. Fig. 2 is a plan of the safety device as seen from underneath, the governor and latch being omitted. Fig. 3 is a side view similar to Fig. 1, showing the safety device in its normal or latched position. Fig. 4 is a plan view similar to Fig. 2, but with the governor and latch included and showing the parts in the same position as in Fig. 3.

In Figs. 1 and 2 are shown channel-irons A, forming the lower cross-head of an elevatoroar. They correspond to a safety-plank. On these channel-irons are mounted jaw-plates B, which are bolted to the guide-shoe stands orbrackets O. (Shownonlyin Fig. 1.) There are three bolts D in each bracket and jawplate, as shown in Fig. 2.

' The gripping-shoes G are mounted on levers E, pivoted on pins F, as shown in Fig. 2. On the inner ends of these levers are rolls I'I, there being two rolls on each lever mounted on opposite sides thereof and on a common axle. Between the pairs of rolls wedges J and J, Fig. 2, are placed. Wedges J are enlargements of the ends of rods K. Wedges J are pivoted to the ends of the rod L. Rods K are tapped into the head N, and the rod L is tapped into the head M. Rods K pass through clearance-holes in head M and the rod L passes through a clearance-hole in head N. Between heads N and M is a helical spring. This spring tends to force the two heads M and N apart and thereby draws the wedges J and J inward, thus applying the grip. Be-

tween heads N and Q are toggles P. The

rod L passes through the head Q and is provided with a shoulder which bears against the face of the head Q, as shown. hen by the operation of the toggles the heads Q and N are forced apart, the rods K and L are pushed outwardly, thus releasing the grip, and the spring 0 is put under compression. To set the device, a pin P, which is pivoted at the joint between the links of one of the toggles, is caught at a latch R on a rod R, which is pivoted to the other joint of the toggles. This rod R has pivoted to its lower end a rod S,'which can be adjusted in length, and is pinned at its other end to a pivoted lever T.

In the drawings the safety is shown in the position of gripping. \Vhen the device is set, the upper end of the rod T is brought into such position that the balls U of the centrifugal governor U will strike it on any large increase in the speed of the car, thus releasing the toggles and applying the grip. The governor is attached to a drum or pulley V, which is one of a pair of pulleys V V, mounted on the channel-irons A. A rope IV, which is fastened at the top and bottom of the shaft, is snubbed around the drums or pulleys V and V, as shown.

The guide-shoes X are carried in the guideshoe stands or brackets O, and the grippingjaws G grip the T-rail guides Y.

It will be seen that the device here shown is very certain in its action, because the speedgovernor may be made to strike the latch with great force, so that the grip will be applied whenever the speed exceeds the limit. It will also be seen that the grip at the two pairs of gripping-shoes will be equalized without respect to wear or irregularities in the shape of the parts, because the actuating-spring is attached at one end to a head to which the rods K are pinned, and is attached at the 2. A safety device consisting of the combination of two safety-catches, toggles connecting them, a spring to operate the toggles and apply the grip, means for holding the toggles with the springnnder strain, and a governor to release the spring, substantially as described.

Signed by me at Bloomfield, New Jersey,

this 9th day of December, 1896.

CHARLES R. PRATT. Witnesses:

DANIEL 0. SMITH, P. R. RITTERBUSCH. 

